I typically like to browse for new and used motorcycles on:

I don’t think its on a web site and I don’t know how they do it in your state/county,.. but here in Texas (254 counties) when the number of vehicles seized, confiscated, and abandoned gets to the point of putting pressure on the lots storing them, they are auctioned off. When this happens it is generally published in the newspaper with 30 days notice. In Tx its has to do with due process of civil law… that gives the registered owner time to file an appeal/ claim for return of the property if the fees against it are paid. The lists of the vehicles can be obtained from the county and quite regularly have motorcycles….happy hunting.

Depends where you are located.

In Australia, Fowles Auctions have written off/seized motorcycle auctions.

In other countries contact your local law enforcement agency, they should be able to point you in the right direction. If not maybe tow truck drivers may know.